Why doesn't the PMDG 747-400/400F have "wingviews"?

The decision to exclude the wings from the virtual cockpit model was
made for performance considerations. The wingtips are barely even
visible from the real plane's cockpit and the pilots need to crane their
necks against the glass to even see the winglets.

It is possible to create wingviews from the external model in
spot view by using a custom camera utility such as Walk and Follow.